1) Field of the Invention
The invention herein relates to a brake lever structure for the synchronized control of front and rear wheel brakes comprised of a braking structure installed between a brake lever and a brake lever mount and, furthermore, the braking structure is capable, when the brake lever pulls the linkage component, of simultaneously actuating pull rods movably conjoined to the two sides of the linkage component which are drawn back and travel in parallel towards the guide holes of the brake lever mount; furthermore, when a vehicle equipped with the invention herein is ridden, if any of the two brake cables become severed, the cable remaining intact is still capable of effectively actuating either the front wheel brake or the rear wheel brake and as such, the braking structure is not only capable of maintaining the synchronized application of the front and rear wheel brakes and at an equalized force, but also of ensured braking capacity even when a brake cable is no longer intact to enhance braking stability and performance and thereby provide greater safety.
2) Description of the Prior Art
A conventional brake lever for synchronized front and rear wheel braking such as the type introduced under U.S. Pat. No. 5,845,539 and indicated in FIG. 1 and FIG. 2 is comprised of a brake lever 1 on a motorcycle or bicycle and, furthermore, the said brake lever 1 is installed to a brake lever mount 2; wherein, front and rear guide holes 211 and 212 are formed at the front end of the said brake lever mount 2 to provide for the insertion of a front and a rear brake cable W1 and W2; front and rear slots 2111 and 2121 are respectively formed at the upper ends of the front and rear guide holes 211 and 212, and a hidden slot 22 is formed at the rear end of the said brake lever mount 2; a linkage slot 11 is formed at the cable pulling position of the brake lever 1 and, furthermore, a figure-8 shaped link plate 12 is movably conjoined to a pull rod 14 and inserted into the linkage slot 11, when the front and rear wheel brake cables W1 and W2 are drawn simultaneously for brake application and, furthermore, utilizing the seesawing motion of the pull rod 14 as well as the unique ascending and descending movement capability of the figure-8 shaped link plate 12, if the front and rear wheel braking action is imbalanced or the front and rear wheel brake cables W1 and W2 become slightly slackened, correction by the pull rod 14 and the figure-8 shaped link plate 12 enable a simultaneous braking action at the front and rear wheels; however, in actual utilization, the structure of the said brake lever 1 is inadequate in terms of performance and can be further refined and improved, with the general shortcomings summarized below.
1. Although the conventional braking structure consists of a figure-8 shaped link plate 12 movably conjoined onto the pull rod 14 and is capable of providing, by means of the seesawing motion of the pull rod 14, for the correction and maintaining of synchronized braking by the front and rear wheel brakes, when the said braking structure is in the process of brake actuation, since the pull rod 14 sways to the left and right in a seesawing state during braking, while capable of synchronizing front and rear wheel brake application, the front and rear brake cables W1 and W2 are not drawn upon equally, with the resulting shortcoming being an imbalanced application at the front and rear brakes that causes the sudden stopping of the vehicle and a subsequent leaning over that adversely affects riding safety.
2. Since the conventional braking structure achieves correction by means of the pull rod 14 and the figure-8 shaped link plate 12, when one of the brake cables are severed, the brake lever 1 can only draw back the pull rod 14 no longer connected to a brake cable (the pull rod 14 without braking capability) such that when the brake lever 1 is pressed down once again, the pull rod 14 still connected to a brake cable actuates brake application, but the limited pulling distance of the brake cable precludes the attainment of effective braking performance, which results in compromised riding safety.
Therefore, the inventor of the invention herein conducted extensive research and design efforts to improve the conventional product which, following numerous testing and refinement, culminated in the successful development of a brake lever structure for the synchronized control of front and rear wheel brakes of the present invention that completely eliminates the shortcomings of the prior art and, furthermore, offers significantly increased practical performance.